Clip machines of the specified kind are used typically for portioning and closing sausages with a liquid to a firm pasty or even granular content. In that operation firstly the filling material is introduced into a tubular case (skin) and thereafter divided up into portions in a first working cycle by means of displacement elements. For that purpose the displacement elements constrict the tubular case in the radial direction and displace the filling material which is in the constriction region in the axial direction—with respect to the axis of the tubular case. A tubular plaited end portion is thus formed in the constriction region. In the next working cycle one or optionally two closure elements (clips) are applied to the tubular plaited end portion formed in that way, by means of two (or four respectively) closure tools which are moved towards each other, and the closure elements are closed around the plaited end portion. The closure tools respectively include in paired relationship a male die and a female die, between which the clip is shaped around the sausage during the closure operation. In the case of two clips which are closed around the plaited end portion in mutually juxtaposed relationship (dual clip arrangement) the plaited end portion can be severed therebetween by means of a blade in order to separate the sausages. Thereafter the displacement elements, the closure tools and the blade are moved back into their starting or open position. A working cycle is thus concluded. The description hereinafter relates to the simple arrangement of a pair of closure tools. It can however be readily applied to a dual clip arrangement.
At least one of the closure tools (male die and/or female die) is mounted to the closure lever described in the opening part of this specification and effects thereby during the closure process a pivotal movement which is substantially radial—with respect to the axis of the tube—around the pivot axis. At the same time and/or subsequently to the pivotal movement effected by the closure lever with closure tool from the open position thereof into the closed position thereof, the second closure tool is also brought into engagement with the first closure tool to close the clip or clips, in a pivotal movement or a linear movement or a combination of both forms of movement.
In such clip machines, there is generally provided a cam drive which takes off the movement of the closure lever from a cam disk by means of a cam roller. The drive element typically provided is a lever arrangement which transmits that movement to the closure lever. As an alternative or in addition to the cam drive the assembly may also have a linear fluid drive, typically a pneumatic drive.
In that case very high forces (up to 15 kN) are applied to the closure lever or levers by way of the closure tools. On the one hand that results in a production of noise which is unpleasant to the operating personnel while on the other hand it means that the closure lever must be of sufficiently great dimensions for it to withstand the loading. The latter in turn results in the closure lever being of a great weight and thus results in a high mass moment of inertia. As the motor drive including all drive elements (cam disk, cam roller and lever arrangement) cannot be designed to be of just any size that may be desired, the operating speed of the clip machine also cannot be readily increased.